WordNet (r) 3.0 (2006):

googol
    n 1: a cardinal number represented as 1 followed by 100 zeros
         (ten raised to the power of a hundred)

Moby Thesaurus II by Grady Ward, 1.0:

25 Moby Thesaurus words for "googol":
   astronomical number, billion, decillion, duodecillion, googolplex,
   infinitude, infinity, jillion, large number, nonillion,
   novemdecillion, octillion, octodecillion, quadrillion,
   quattuordecillion, quindecillion, quintillion, septillion,
   sexdecillion, sextillion, tredecillion, trillion, undecillion,
   vigintillion, zillion



The Free On-line Dictionary of Computing (30 December 2018):

googol

    The number represented in base-ten by a one with
   a hundred zeroes after it.

   According to Webster's Dictionary, the name was coined in 1938
   by Milton Sirotta, the nine-year-old nephew of American
   mathematician, Edward Kasner.

   See also googolplex.

   (2001-03-29)